modelPartialHeatExchanger

Partial model for heat exchangers

Extends from Buildings.Fluid.Interfaces.PartialFourPortInterface, Buildings.Fluid.Interfaces.FourPortFlowResistanceParameters, Buildings.Fluid.Interfaces.LumpedVolumeDeclarations, Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.ThreeWayValveParameters.

Information

This module simulates a heat exchanger with a three-way bypass used to modulate water flow rate.

Parameters

Type	Name	Default	Description
Boolean	homotopyInitialization	true	= true, use homotopy method
Modelica.Units.SI.Efficiency	eta		constant effectiveness
Dynamics › Time needed to open or close valve
Boolean	use_strokeTime	true	Set to true to continuously open and close valve
Modelica.Units.SI.Time	strokeTime	30	Time needed to open or close valve
Modelica.Blocks.Types.Init	init	Modelica.Blocks.Types.Init.InitialOutput	Type of initialization (no init/steady state/initial state/initial output)
Real	yThrWayVal_start	1	Initial value of output from the filter in the bypass valve
Three-way Valve
Modelica.Units.SI.PressureDifference	dpValve_nominal	6000	Nominal pressure drop of fully open valve
Dynamics › Nominal condition
Modelica.Units.SI.Time	tauThrWayVal	10	Time constant at nominal flow for dynamic energy and momentum balance of the three-way valve
Advanced › Nominal condition
Modelica.Units.SI.Density	rhoStd	Medium2.density_pTX(101325, 273.15 + 4, Medium2.X_default)	Inlet density for which valve coefficients are defined

Components

Type	Name	Default	Description
Buildings.Fluid.Actuators.Valves.ThreeWayEqualPercentageLinear	thrWayVal		Three-way valve used to control the outlet temperature
Buildings.Fluid.HeatExchangers.ConstantEffectiveness	hex		Heat exchanger

Revisions

November 16, 2022, by Michael Wetter:
Changed riseTime of valve to be 30 seconds to make it the same as the rise time of pumps.
April 9, 2021, by Kathryn Hinkelman:
Added dpValve_nominal to avoid redundant declaration of dp2_nominal.
April 14, 2020, by Michael Wetter:
Changed homotopyInitialization to a constant.
This is for Buildings, #1341.
June 30, 2017, by Yangyang Fu:
First implementation.